益生菌对锦鲤幼鱼生长性能及血液、肝脏和肠道组织中相关免疫基因表达的影响

为研究饲料中添加益生菌对锦鲤幼鱼生长性能和相关免疫基因表达的影响,以初始体重为248.13±4.71 g的锦鲤幼鱼为研究对象,在小型循环水养殖池进行60 d的养殖试验。对照组投喂无益生菌添加的普通商品饲料,试验组投喂在普通饲料中添加枯草芽孢杆菌(Bacillus subtilis)、丁酸梭菌(Clostridium butyricum)和粪肠球菌(Enterococcus faecalis)、枯草芽孢杆菌/丁酸梭菌/粪肠球菌(1∶1∶5)配制成的4组试验饲料,试验饲料的益生菌最终浓度为109 CFU/mL。结果表明,单一菌种或复合菌种的益生菌对锦鲤幼鱼的生长均有显著的促进作用(P<0.05),且对各组血液中酚氧化酶原(phenoloxidase activating system,proPO)、溶菌酶(lysozyme,LZM)和肝脏中抗菌肽(hepcidin)的相对表达量均显著上调(P<0.05),对各组肠道中GST相对表达量有所升高。与对照组相比,复合益生菌效果最好,增重率最高为38.13%,特定生长率提高25.58%,血液中proPO和LZM相对表达量分别升高3倍和2倍之多(P<0.05),肠道中谷胱甘肽S-转移酶(glutathione S-transferase,GST)相对表达量升高了32.45%(P<0.05),肝脏中Hepc相对表达量升高了76.82%(P<0.05)。试验结果提示,在饲料中添加单一/复合益生菌,均可有效提高锦鲤幼鱼的生长性能,以复合益生菌使用效果更好,且proPO、LZM、GST和Hepc免疫基因相对表达量在不同程度上均高于对照组,可见枯草芽孢杆菌、丁酸梭菌和粪肠球菌可以作为益生菌应用于锦鲤养殖。

Effects of Probiotics on Growth and Blood,Liver and Intestinal Tissue Immune Relatd Gene Expressions of Juvenile Koi Carp(Cyprinus carpio)

A 60d feeding experiment was conducted to study the effects of adding prebiotics to the feed on growth performance and non-specific immune gene expressions of juvenile koi(Cyprinus carpio)initial body weight(248.13±4.71)g].Four experimentsl diets were formulated in control 0(commercial fodder),Bacillus subtilis,Clostridium butyricum,Enterococcus faecalis and with mixed diet comprising Bacillus subtilis/Clostridium butyricum/Enterococcus faecalis at the ratio 1∶1∶5,the final concentration of probiotics was 109 cfu/mL.The results showed that all probiotics groups can significantly improve the growth of juvenile koi(P<0.05),and the relative expression of propo,LZM in blood and HEPC in liver of each group were significantly increased(P<0.05),and the relative expression of GST in intestine of each group was increased.Compared with the control group,the compound probiotics can better effect,its highest WGR was 38.13%,and SGR was increased by 25.58%,the relative expressions of phenoloxidase activating system(propo)and lysozm in blood were increased by three times and two times respectively(P<0.05),and the glutathione S-transferase(GST)phase in intestine was increased by three times The relative expression of hepcidin in liver was 76.82%(P<0.05).The experiments indicated that adding probiotics to feed can significantly improve the growth of juvenile koi,and the effect of using compound probiotics was better.The relative expressions of proPO,LZM,GST and hepcidin immune genes were higher than that of the control group in varying degrees.It can be seen that Bacillus subtilis,Clostridium butyricum and Enterococcus faecalis can be used as probiotics in Koi culture.